If there’s one thing that can ruin a nice summer evening, it’s the stinging bite of a billion mosquitoes. We’re babies about bug spray; if it’s poisonous enough to keep the bugs away, it can’t be good for our skin. That’s why it’s good to see inventions like the silicon nanoparticle clothing being developed by Portuguese tech company Nanolabel. The clothing is imbued with particles of silicon dioxide which are, in turn, impregnated with a top-secret mosquito-repelling substance.

The anti-mosquito substance is not permeable to human skin and was classified in the lowest degree of toxicity by the FDA. But the mosquitoes stay away: in tests, 81 percent of mosquitoes were repelled and 89 percent were kept from feeding. The repellent only stays in the fabric for up to 90 washes, so the treated clothing wouldn’t be a permanent solution. But items like lightweight jackets that don’t have to be washed after every use might be the ideal application for Nanolabel’s technique.